Build
a Computer Desk, in One Weekend, with One Sheet of Plywood, For Under $100.00
Attach the Legs to the Desktop
Apply glue to the marked area, where the yellow squiggles are. Put leg in place, squish glue around, remove leg, let glue air dry a few minutes, then put leg back in place. You will have to come up with a way to hold it in place till the glue sets.
I leaned one leg against a cupboard door handle. The other one I braced with a board propped up against it. If you don't do this step well, the whole project will be delayed. The hard part for me was waiting till the glue was set.