Remove the reinforcing hardware and liner. Drill a hole where you want the stud and inlet the forend channel for a threaded plate (drill and tap a piece of scrap) or flat nut so it will fit under the forend liner. Many times I use the Hillman T-nuts for wood work in the Lowe's hardware section. You'll need to cut off the threaded portion to the proper length so the stud pulls up tight, which can be done with a rotary tool and a cut off wheel. Trim the stud to length and put it all back together. Use some red thread locker or stake the stud to the nut/plate if you like. If the action binds or drags you need to inlet the nut/plate a little deeper. If you plan to use a bipod, come back from the rear edge of the gas block at least 1.75" when drilling the stud hole and most all stud attached bipods will fit perfectly.
You can also remove the loop from the gas block, make sure it's drilled all the way through and mill, grind or file the ends until they're nice and flat and a regular swivel will lock in place properly. If you don't the swivel will fit, but probably won't lock due to the width.