need some help moving stuff for 20's on s10

i know this has been hashed and rehashed, but i need some help on moving stuff in my engine bay. how exactly do i move up the slave cylinder, and where do i need to move the main wiring harness? Is that big rubber boot on the wiring harness that goes into the firewall a plug or just a gusset that runs thru the firewall? If it's a plug, how do i unplug it? Do i have to cut the boot, or just work it out?