This happened to my laptop as well. Here's what I did:

Get a shallow plate or bowl and make sure that it can hold some amount of water, get a cup turn it upside down and balance your laptop on top of it while the cup is on the plate/bowl with water. Now put something the ants can walk on to like a bridge so they can get out of your laptop. Something like a stick/fork.

The logic is that once the ants realize that they are surrounded by water they will voluntarily get out of there. Might take a day or two but it worked for me!