Windshield washer reservoir tank is leaking how do I replace?

You must remove from it's mount and empty out any fluids that is in tank.fill the tank with water and locate where the leak is coming from. wash tank a few times and the let dry upside down. Get some sand paper (80  grit course) and sand area where leak is, clean area with a vacume or clean rag.you can buy a 2 stage epoxy that comes in an injection form and squeeze it out on a pc of paper and then get a q-tip and mix the 2 components together, fill the crack or hole generously with the q-tip, if you have to,let dry for 24 hours and mix more and put more on. let dry another 24 hours, replace tank back in it's place and you've solved your leak. (epoxy does wonders if its used properly.
Frankthetank