Ok i no there are trainers out for this now but sometimes they don't work for people so here's a way that i just found and it works
1.) Open up your UCE, i use KiKi's UCE but this should work for any of the UCE's.
2.) Go in combat arms go to your backpacks and equip your standard backpack.
3.) This backpack adds +1 slots so Alt-Tab and search for value 1
4.) Then go back in game when that's done searching and Equip your advanced backpack.
5.) Alt-Tab and search for 2 this is for the slots that the advanced backpack adds.
6.) Repeat steps 3 - 5 until it stops at about 72 values this is what mine stopped at yours could be more or less.
7.) Go in game and UN-equip all of your backpacks (don't have any backpacks equipped) go to your UCE and look in the list of values you have look for the values that says -1 there should be about 4 or so.
8.) Add all the -1 values to your cheat table or address list and reset the values to 4 or 5 then freeze all the values.
9.) Exit the shop and go back in and there you go you have an extra 4 or 5 slots.
**Note** I suggest your only do 4 because if you do 5 as your value you have a Santa's sack and it is very noticeable.
Hope this helped you guys Happy Hacking
This is my first tutorial so if it was good or i need to improve anything just tell me thanks guys!
if you using mhs, i had to actually search -1, and even though i searched -1 i got theses pointer with big 6 digit values, but i froze them and it worked. Also i learned how to get the tactical vest...lol