Go to the rogue trainer and ask him where to skill up. He will tell you where you can find footlockers and chests to get you those 4 points. Other options is get some Dark Leather Gloves, or spam trade to open lockboxes, if there are any that are not grey at that level...I am too lazy to look it up.
I had the same problem, my solution was to get a leatherworker to craft Dark Leather Gloves which add 5 to your lockpicking level. That way you can open all the boxes in your bank and level really fast... I then kept the gloves in my bank for use when close to the next levelling target.
I did just as Ceroc said, and it turned out to be the best solution. Went straight to the bank and lvl up to 220! Put the gloves in the bank so I can use them if I am lacking 5 points when all is grey at the next crossroad...
best place to lvl from 120-->180 its wetlands...bluegill marsh...go around the camps and ther are boxes everywhere..with different lvls...just spend 20 mins and u get like 40 lvls ;)