2004 Mercedes SL350 Cant open the Boot / trunk


It appears I have an electrical problem on my 2004 Merc SL350, the 20amp fuse keeps blowing which means the central locking does not work, I have to use the key to lock / unlock the doors, but even with the key I cannot open the boot / trunk.  I have tried putting a new Fuse in but it blows straight away, can't find anything on youtube, so how do I open the boot ?  Suggesting please.