i have manual locks on my seirra 2002 truck and have difficulty locking or unlocking the doors

What is your question?

almost impossible to lock or unlock doors manually with the key

What makes this problem better or worse?

trcuk has manual locks and it is almost impossible to turn the key in the door lock to get it to open

How long has your 2002 GMC Sierra 1500 had this problem?

since I bought the truck