I am not sure it that could help, but I would probably use an exacto and and slide it on the top of the trim. It could limit the damage on the wall when you remove the trim.

At least score/cut the caulking on top and bottom of the trim so it doesn't tear the paper off the drywall. Maybe get a one inch metal putty knife and slowly work your way under trim as you pry off. After you get trim off use a flat razor blade to get caulking remains on wall. Do everything you can not to tear that paper, pain to fix properly, for me anyway.

You will have to skim coat, sand and prime and paint drywall to cover the areas where drywall paper was torn. Lots of videos on YouTube for that. I've done that when removing wallpaper, torn drywall paper, pain to fix, sanding and getting it to look right.

To replace trim get real wood, or that vinyl stuff even, painted. It looks like they used that particle board type wood that will absorb water and swell when it's wet, bad/cheap choice for a bathroom.

I assume that you have learned that mdf baseboard is a no-go in bathrooms? Replace with PVC or real wood. Wouldn't hurt to back prime the new baseboard, too.

You shouldnt have to glue it to the wall either. Nail in in, and if you think it needs caulking, just caulk across the top to the wall. I dont like baseboards caulked, I like them to fit well enough, that they shouldnt need that. That used to never be done, but, in recent years, it seems to be done all the time. I like my baseboards to be be easily removed, if I want to remove them for something, and then be easily put back, when I am done with what I am doing.

You are probably having the same problem I have with keeping water in tub during showering. I finally found something that works for me. Now I don't have to yell at my son anymore to be more careful.

I got these two things from Amazon:

https://www.amazon.com/SlipX-Solutions-Curtain-Install-Adhesive-Free/dp/B001BVMS2K

And:

https://www.amazon.com/Magic-Splash-Guard-Prevent-Splashing/dp/B00NOG5PWA

The splash guard is very sturdy, much better than a few I've purchased in stores and are flimsy and thrown away because we're useless. I only purchased on for the shower head side. I did run a small bead of caulk around it though. I do have porcelain tub, yours appears to possibly be fiberglass if that makes any difference.

Fill it, sand it smooth, and prime it with the oil based primer, and then just paint it with regular oil based paint after repairing what caused the problem in the first place.

FYI, I've never used a oil based paint, a good latex paint would be fine. When you go to the buy paint tell them you will be painting a bathroom and a additive can be added to paint to deter mildew because of high moisture in bathroom. Use a primer (I've only used a latex water based/water clean up primer or paint) over areas you have skim coated to fill in voids left where drywall paper was torn. Pollyfila must be what it's called in Canada. In US it's just drywall mud. I'll Google it and come back.

Is it this stuff. It looks more for use with old fashioned plaster wall and more for use to fix cracks and smaller holes. Also it does say in instructions to use oil based paint, never seen that.

https://www.polycell.co.uk/product/polycell-multi-purpose-polyfilla-ready-mixed/

I'll find something about drywall mud now. Go to hardware store and ask for drywall mud/compound and get the tools. You will probably need one of those larger 16" across drywall things because you have a larger area and small ones don't work well, also sanding stuff. The hardware store people can help you find what supplies you will need.

https://youtu.be/ihv9XajjPFs

And this:

https://youtu.be/U3ISTc3tpxw

There is a bazillion videos on YouTube on drywall repair.

Thanks! Pollyfilla is just drywall hole filler, it is one of the brands! I've filled holes all over my house, but I wasn't sure of the procedure for a washroom. I am going to go with latex paint, not oil. We have used a mix of Aura and Regal Select from Benjamin Moore and have been happy.

A tip for future reference: place a putty knife between the wall and your prybar to protect the wall from holes, as you discovered can happen. You should also be hammering the prybar down so it actually gets down in between the baseboard and wall for more leverage. This should be done down the length of the base before you even start to pry it off. If you’re not doing this, that’s probably why your base is breaking off in jagged pieces - the glue is holding the other pieces tight to the wall because the bond hasn’t been broken.

So after following the other posters’ advice of first scoring the top of the base, work your way lengthwise down the base hammering the prybar in between the baseboard and wall wiggling a little to break the bond. When that’s done, THEN you can pry it off while placing a stiff putty knife between the wall and prybar.

So - I used a thin crowbar, but it still ripped the rest off! Lesson is: NEVER USE CAULKING!!!! I'l just have repair it and use a few coats of primer... All for a bloody baseboard!