Either: Donate money to Andrew McCluskey via PayPal: . I recommend the donation sum is what you feel the font is worth to you and what you feel is right for what you're getting from the font - I make less from doing this than you might think! Or: See here for alternatives! nalgames.com/donations/
This grants you, or the organisation/etc you represent, the ability to use this font infinitely for non-commercial/non-profit (option 2) or anything whatsoever (option 1). I do not restrict what you want to use it for, anything goes.
Thank-you for downloading this font and I hope you find a use for it!