Swapping out brass trim and faucet in Tub

[bartgrometer]

Attached is a picture of a tub we are going to try and "modernize" by swapping out the brass. The problem is I can't figure out how to remove the trim or the faucet. There doesn't seem to be a set screw for this faucet. Any ideas on how to remove the trim and faucet? Thanks!

 

[Redwood]

You need access to the underside...

Here is a link to a parts diagram for a faucet similar to yours...

 

[bartgrometer]

Thanks. Access will be difficult. I've attached a couple more pictures. Does this mean tile has to come out in order to replace faucet?

 

[Redwood]

Well...

Can you reach the nut and connection to work on it?

You need to!