It's a good idea to step up the wiring to at least 4 guage in the process of upgrading the alternator. Other than that, it's just changing the alternator out and wiring it.
im running 2 jl 500/1's and 1 alpine mrp-f240 amp. 2 subs and one componant set up front. i wanna upgrade to a 150 amp HO alternator. I am probably gonna run 2 gauge from battery to trunk. What size whould i need for the alternator upgrade???