What's so hard?
- Drill bolt size holes in whatever you are going to put up.
- Temporarily put against wall and use bolt holes to mark/drill holes in drywall.
- Drill holes in DW the diameter of the molly insert
- Insert mollys
- Tighten bolt so molly expands behind wall and the collar flange sets slightly into DW
- Remove bolts
- Put bolts through what you want to hang. A washer under the head may be needed depending on how big a hole you drilled.
- Screw bolts into molly inserts
If you ever remove your shelf all you need do is swipe a bit of spackle or DW compound over the sunken collar of the molly. Easier than fixing a hole from a plastic insert, lots easier than fixing a large hole from a toggle bolt or the big threaded DW anchors.