Volvo Repair: Replacing left blinker V70, headlight assembly, turn signal

Question
I have a cracked turn signal on the left (driver's) side and it needs replacing. I have located a replacement via the internet for about $18 instead of the $450 quoted by the dealership. How do I replace this lens myself? Can it be done?

Answer
Felix.  They must have quoted you for a headlight assembly.  There is no way they would do that for a turn signal assembly.  Those just pop out if that is what you are talking about.  If you want to replace the headlight glass then we  can go into that.  Let me know.  Roger