If you were in a hurry you could just tape it on, but soldering will give a much stronger and better connection.
Pay attention here, Zebu00. When you solder a joint, it is going to be waaay stronger than a twisted joint. It is also going to have better conductivity. The only thing better is a wire-wrapped joint.
When you are prototyping, you want your joints to be strong and secure, otherwise noise and errors will creep in, and you'll be left wondering "is it my code, or my hardware?" - and tearing your hair out to find a problem being caused by a bad connection (this applies to solder joints as well - one bad solder joint can ruin your week!).
I have an h-bridge to attest to this fact. In this bridge, I had to use alligator clip jumper cables for some of the connections, because the case of the transistors I was using was the collector (TO-3 case) of the transistor - so I had to connect them using the jumpers on the breadboard I was using. I kept having a problem where I could get the motor to run one direction, but not the other. I thought I had a blown transistor or two on one side of the bridge; I knew it wasn't the software because I could see my status LEDs showing I had current to the bases of the transistors. The maddening thing would be that sometimes it would work briefly, especially after I had swapped transistors or such. Then it would stop!
It ultimately turned out to be an intermittent fault in which one of the jumpers wasn't well connected with its alligator clip(s) - replacing that jump (after messing for a long time with the circuit) cured it.