Call Lester for lockpicks, then buy a Speedo (the Clown Van also works). Pacifists cannot start this.

Wait until night (about 18:00 to 06:00 LS time). Sit in the driver seat of your own van and press G to start.

Park near the marked house and lockpick the front door. House locks take a few rounds. Anyone close when the lock opens is part of the job.

Inside, grab loot and stash it in the back of the van. Some houses have an alarm you can disable. If it goes off, watch for cops.

When you have enough, drive the van to the marked buyer and press E to sell. Stay with the van. Houses need time before they can be hit again.

This buyer is part of the burglary, not the nighttime Fence who buys heist goods.