we have lived in base housing all of our lives and have managed to patch up everything, even if it means kleenex and white toothpaste Seriously, that velcro strip should come up with a hair dryer and a putty knife and if any paint does come up, white shoe polish and a coat of wax works great You might also just use a few pieces of the velcro on the sill, rather than the whole strip - like some at each end and in the middle maybe.