Unless it has been replaced before and socketed, yes, it will need to be desoldered and resoldered. If you need to replace, it's a smart idea to put a socket there first (just in case you ever need to replace it again)
Also, as I was informed before fixing my board, it's wise to order enough chips to cover replacing all of the 2101 RAM chips as after replacing one, you may find another one that is bad. (there are 8 on the board typically). I ended up replacing 1 bank of 4 chips to get mine working. If you need to get some chips, I got mine from Riptor (look him up).. he had a suitable replacement that works fine.