Step 1: Materials List
PVC (about 1 inch size)
Grippy pad (not sure what it's called - you will recognize it in the picture)
Hot glue gun
Hack saw (or similar)
Step 2: Measure
By the way:
Length = Measurement left to right across your laptop when you view it from the front.
Width = Measurement from front to back of laptop (latch to hinges) when you view it from the front.