I would just hard solder them to the raspberry pi, you can find some wire to use in the elab (just donate what you think it would cost to the donations bin).
The only area you’ll have problems soldering on the raspberry pi is the ground pin as it’s very well thermally connected to the ground plane. Make sure you use on of the met-cal irons with a “wide” chisel tip and it should be doable.
Just hold the soldering iron in reverse Seriously though, just use the soldering iron to heat the joint and then pull the wire out when it starts to come easily.