u/Impossible_Drama2704

Hi all - I am using a retread kit on my stairs and I have a question about the best way to level the new tread. These steps were previously carpeted and have definitely seen some miles. They are still in solid shape with no squeaks, but several treads slope forward just slightly. I want to level the new tread when attaching… can I add shims directly underneath (sandwiched between new tread and old tread)? Glue/nail them down and use a couple per stair? Or can the adhesive (PL Premium) be manipulated to do the leveling? I am just not sure if adding shims under the trim will cause any ”squeaky” situations down the road.