Well I cannot see the pic anymore but you need a plastic welder, before the flame war begins yes they exsist. It is a heat gun that uses plastic rods basicaly and it repares the plastic. 1st you have to cut the cracked part into a v shape the apply the welding rod with the welder, then sand it down til it is smooth, then get some flex agent ( ask for it at any bodyshop supply store) and some 2k primer apply the flex agent then wait the reccomended time on the container ( they vary from brand to brand, tipical time is around 15mins and no longer than 25min) then apply the 2k primer. The next day after everything has dried you will need to wet sand the 2k primer until it is smooth and even with the rest of the plastic area. I know this was kinda just an overview and it is not as complicated as it sounds
