To make things easy, hop over the wall just to the left of the wrought iron gate.
Once over, enter stealth mode and go over to the van with the Gardener. Knock him out then start over to the East, going around the house. Climb on over the wall, cross in front of the double garage and up over the next wall. Go to the corner and wait.
Tyler is swimming laps in the pool while the woman sits in the hot tub. Wait for Tyler to get out of the pool. Now move out from behind the corner and stealth over to the reclining chairs. You will find the clothes just past the second chair. Done quickly enough, neither of the people will notice the theft.