Solder is vastly preferred, as is heatshrink tubing.

You can use solder heatshrink connectors that are used for field repairs and can be found in car shops.

Just insert a clean stripped wire into both ends and heat it up with a lighter - solder would melt making a stable connection and heatshrink would shrink, isolating and mechanically protecting the connection.

I see.
Well, If I HAVE TO spend money, I'm just buying the adapter.