How do you disable the alarm completely from the starter of a 93 Suzuki Sidekick when sometimes it won't start because the alarm disables the starter?

Exactly how is going to depend on who installed the alarm. There would be a relay which (likely) breaks the starter cable. You'd need to locate this relay and reconnect the starter cable where the relay has been inserted. Not much help, I guess, but for what it's worth.

If you know where the alarm module is you could try tracing the cables from it, or (easier) try tracing the starter cable from the switch until you find a break (tape, splices, whatever) then just remove the inserted cables and join (repair) the starter cable. If anyone has a wiring diagram that would give the colour of the cable, it would help.