water leak from shower tapsd

I have a transit legend 1995/96 and need to replace the shower mixer taps can any one help and guide me and tell me how to get behind the shower wall the easiest way any help would be apprecited

thanks for your reply ian but i have done it now you just take out the cabnet 4 screws and then the sink underneath 4 screws and pull forward that gets you enough room behind the panel to remove the shower tap