Move the drawer to the fully extended position.

The drawer will likely get stuck along some points of its travel. Its OK to hit it with a hammer. Remember the secondary cylinder will be applying tons of force to move it.

If you need to hammer it REALLY hard, either your drawer is hitting something, or the rollers are too tight on the rails. Investigate the cause.

When the drawer is in position, check the rollers again. They should all still be touching the rails.

If one is below the rail, tighten the bolt so the rail and roller are touching.