REWARDS - Respect, $7,000, Quarry job and Heist side-mission unlock
Head to the quarry, marked by the yellow blip. Park in the red marker and get ready for some quick moving. You have 2 minutes and 30 seconds to get into the one truck down in the bottom area, then quickly smash the crates and pick them up on foot (CJ will automatically defuse them). Hop down to the bottom area in your vehicle and get into the dump truck. Smash the four crates, including the one on the moving forklift, then pick up the dynamite and the timer stops. Now, onto the escape.
Security blocks the entrance and you must find another way out. Get on the Sanchez marked on your radar and make your way to the first marker. Follow the markers as you continue up the quarry, taking out the security when you need to do so. There will two guards at the entrance, so take them out and head out of the quarry. After that, head to the drop off point to finish the mission.