Just stop by any Friday or Saturday from 9-1 and ask for the form. You fill it out yourself for your records for tax purposes.
They do have a drop off location for after hours, but I imagine you probably can't get a receipt, or if you can, you'd have to go while they're open later, and if you have to do that anyway, you might as well just bring your donation while they're open and save yourself the trouble.
I dont know if they take donations after hours.
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