If you are going to do it (and i'm not sure that you should)
try this first .... it will come in useful when you try to get the key back.
First you must realise that the space key is usualy a double key (ie there are two deckchair arrangement left and right that holds it all together)
take a paperclip straighten it out - put a 90 bend in it just less than the width of the key.
insert the tool parallell to the bottom of the spacebar and rotate 90 deg .... carefully move left to right ... blow to move any debris as you go.
repeat from the top of the key ....
I stole one of the wife's blusher brushes ... nice long britsles .... carfully "stab" the bristles so they end up working under the key.
if none of this works ... pop the top off ....
you can use the paperclippy thingy to help replace the key ... so not a waste