Random lifter rattle

Motor is new and clean, less then 5000 mi. must have just been a bad lifter, go figure
It should just slide right out, you may have to loosen an intake bolt to get clearance, lay a work-cloth in the valley to avoid blemishing the lifter.
I use a thin piece of welding rod and/or magnet to fish the lifter out/in.
Clean, re-assemble .
Good luck, you should be fine !