What can I use instead of soldering
You do not solder those. You crimp them. They are not actually D-sub contacts but you can use a open-barrel D-sub crimper or something that looks similar for 0.100&quot; female crimp terminals and housing. The official crimp tool for them is hundreds of dollars from the manufacturers that make the contacts so don't use them unless you need certification.
They go by many names from different manufacturers. Here is an example from Molex. If you are wondering what the difference is between the crimp terminals in the first two images, the difference is the first is high-force and the second one is normal force. Male crimp terminals also exist (and I think they use different crimp housings too).



Note crimping can take more finesse than it initially appears. Among other things, crimping the wrong depth into the terminal can bend the entire terminal (same way smashing the top center of a box pulls the sides and corners inwards) and make it not slide into the crimp housing. Also stripping enough so good contact is made with both conductive core and insulation for good grip. Crimping too hard with too small a die size means the force to pry the terminal out of the crimper ends up bending it. Particularly an issue when using crimpers not made specifically for your terminal (which cost hundreds of dollars).
Get more than you need and practice about five times so you can see what can go wrong.

From GreenLee

From Engineer