Go to an Art Supply store and get some solder that is used in Stained Glass work. It is mostly lead with very little silver.
Use the paint-on type of flux and heat it first, then do the soldering joint.
Finally, wash everything down with a solution of baking soda and water to neutralize the acid from the flux. Or it will slowly eat a hole in the brass.

It's not hard. Just be patient.

CC.