Pretty hard to solder without solder. I feel your pain, since even cheap soldering irons can cost a full week’s groceries.
My suggestion is to try crimp pin connectors. Try your electronic parts stores. You don’t need the fancy crimping clamps: with some patience you can use regular pliers. Insert the two wires to be joined and squeeze tight! Once joined you can apply some shrink tape for insulation, weather resistance, looks, etc.
Depending on where you are in the world, a packet of these connectors should not cost you more than a couple of cents.
Thanks heaps you really helped but I don’t know if I can use those thing on mini dc motor on battery packs. If you can put them on live wires pls reply if not thanks heaps anyway!!!
see my pattern:+1: thanks heaps