change shape of picture?

[legepe]

Hi everyone
I am new and just learning the basics of PSP and want to know if the following is possible
I have a photo of a bathroom displaying a P-Shaped bath.
Is is even possible using PSP to change this to a standard bath (curved edge of bath and bath panel to a stright)
If this is possible how/what tools should I use?
Any advice very much appreciated
Thanks
legepe
PS: ive just got a One by Wacom tablet to assist me with this, does this provide a much better control with editing photos.. and is it just a matter of practice as I am finding it very unusual/difficult to use!?

[LeviFiction]

I can think of two options off the top of my head.

1) use the warp brush. This is a drawing tool that lets you push and pull elements of an image distorting them. Start with a large brush to pull big areas and slowly decrease the size to make smaller movements.

Or

2) find a picture of a square bath that might look good, cut it out,and put it on a layer over the original bath covering up the old one.