STEP 1:
Measure the inside of the cabinet from the right to the center of your pipe.
Step 2:
Measure the inside of the cabinet from the left to the center of your pipe.
Step 3:
Measure from the inside front edge of the trim to the center of the pipe.
Step 4:
Before you begin the right side of the mat has Xtreme Mats written along the side. Take all measurements from the top outside edge of the mat. Measure from the right and make a pencil mark for the center of the pipe.
Step 5:
Take all measurements from the top outside edge of the mat. Measure from the left and make a pencil mark for the center of the pipe. Notice your second mark won't match the first mark this is fine. Now make a mark between the first and second line, this is now the accurate center point.
Step 6:
Take all measurements from the top outside edge of the mat. Measure from the front of the mat and make a pencil mark for the center of the pipe. Make sure the front edge of the mat is bent up at 90 degrees.
Step 7:
Now you should be able to make a cross and drill the diameter of pipe you have plus 1/8 of an inch additional.
Step 8:
Take a razor or scissor and cut from the center of the hole to the back of the mat. This will allow you to have a custom fit around your pipes and allow you to waterproof with silicone. Seal around the pipes and along the cut you made from the hole to the edge of the mat and up the sidewalls.