Hired Squad Members

i can't figure out how to upgrade the hired top squad members. it says they're upgradeable, so how do i do it??

 

You need to find your hired Squad members in your "Support Squad" list (at the screen showing your Top Squad group), there is an "Upgrade" option in the same place as the "Add to Top Squad" button is for players.
It costs UN points (depending on how often you do the upgrades, up to 10 points per upgrade) and their stats are increased according to your level and/or battle stats, I´m not sure actually.

 

for me, all i see is an add to top squad button. no upgrade one.

 

that will be becoz your hireds are as strong a you can have them for your strength..
(so button isnt there till you get stronger)

a attacker is 2x your attack and 1x yoru def, a defender is 1xyour attack and 2x yoru defence,

there is only a need to upgraed them IF your top squad isnt able to complete yoru top squad strength.

 

An easier way to to find them is: Click on Squad --> Hired squad members and click on "upgrade"
Done.