You new cable should be long enough to work on. But if it just right at the t-handle, do this:
1) Use the stud push the lead ball up, held them on the ground so that the cable come out all the way.
2) Install the t-handle. Hand tighten the lock bold.
3) Lower the stud until the lead ball at desire location - usually ltitle higher than the shitter mouting base. Tighten the lock nut.