We would prefer you shut the system down first Paul,then there's no need to remove the rkp fuse,
as alarm has said mate, mains power off and disconnect the backup battery inside the control panel,my mention of the fuse to Alarm was mearly a query has to how that particular(yours) behaved on removal of the F4 fuse.
This was not an instruction directed for you,
Make a note of the wiring colours/connectors at the rkp before you remove any wires, simple swap, all the terminals are marked for you.
emanno, November 2012