How many holes did you have... counted 10 plugs. Might have been easier to cut a big circle and retrofit some holes.

 and apply a Box Guy Clamp

Love those BGCs... made a couple myself. 

 and I didn't have the skills to get a IKEA edge finish! 

The secret is to forget the "package included" allen key and go for a "pivot head" stainless,

for that true IKEA masterpiece!

If your first cut is too short... Take the second cut from the longer end... LBD