It appears you're inserting it correctly. It might just be your common3 that's the problem. Try inserting the fix into a vanilla PMEx common3.
the vanilla common3 works for cobalt atm but doesnt work with XP..which is unfortunately the mod i need it for, considering idk how to put wiimmfi on cobalt SD's =_=...so im using LXP for its wiimmfi, as a base, but both their, and vanilla common3's, edited with the fix or not, are incompatible with LXP