Step 1: Take off both clips on side of lense
Step 2: Get hair dryer out and warm up the edges of the lense (make sure the glass is atleast warm when you touch it)
Step 3: Begin to wedge the lense off slowly with a small screw driver (if still not budging much or sealant is very stringy, heat up more with hair dryer)
Step 4: It should be off
Installation is the reverse of the above steps, except when putting it back on make sure you heat up the sealant.