Wheel Wells LWB

[gary2232]

I have a 1972 long wide box. I want to remove the wheel wells to do a little rust repair around the seams and base. First question, should I remove them before I remove bed of truck for some other repairs or is it easy to do with bed in place?? And do I need to use a seam filler when I replace?? It looks like there may be a gasket or some type of seam filler between bed floor??
1.So question one how to remove
2.Do I need to use seam filler or use some type of gasket?
Thanks