There are many types of soldering paste many of which are in a syringe like tube which makes it easy to get the paste in the exact spot it needs to be.
I personally use a plastic opening tool to scoop a little out and apply it gently on the spot I will be working on.
Place the de-soldering wick on the solder joint and put the tip of the soldering iron on it so the wick can heat up and absorb the old solder.
Please remember that logic board components are very fragile and excessive heat can destroy these components.
Lift the wick and the soldering iron up from the logic board at the same time. Failure to do so can cause the leftover solder to harden and solder the wick to the logic board and you could easily pull a logic board pad off.