lift up the bathtub

[Jerome7]

I am retiling my bathroom and a have a tub looking like this. The shower is separate.
I'd like to keep the tub as it was barely used. Thus I am trying to lift it up a bit so I can remove the tiles and slide the new tiles under. Is it possible?

The tub is surrounded by deckmud no access to the bottom. There is a small access form the outside and I can see mudbed under the tub? Is it then glued at its bottom?

I am planning to retile over the current deckmud surround.

Thanks for your advices