The easiest actually is not to glue the windows provided in the kit and bin them! Later, after completion of the painting and decalling (possibly also weathering), you can replicate the windows with stuff such as Kristal Klear, Humbrol's Clearfix or even better if you can find it where you live, Ross's Blue Gel glue (in Walmart's!). All those are easy to apply with a cocktail stick, can be removed easily with water in case of boo-boo, and dry clear!