Use the pointed end of a spudger to pry up and disconnect the white antenna's coaxial connector.

Pry under the rounded edge of the coaxial connector, not the straight edge. If you pry under the straight edge you may rip the socket off of the motherboard.

During reassembly, make sure to put the cable back in its clip on the motherboard.

To re-attach coaxial connectors like this one, hold the connectors in place and gently press them straight down with your finger or the pointed end of a spudger.