Hi, I've got a Pro micro 32u4 that doesn't have the micro usb port (broken). I powered it with another arduino and it did turn on. Is there any way to upload code to it without the usb port? It seems too small to solder
thanks
Research Arduino as ISP
Get a USB cable that is otherwise damaged, cut off the part with the "A" plug and solder the connections to the USB port connections on the Pro Micro. 
Can't solder? Take up knitting instead. 
Use another Arduino to program. It can be repaired but at the price of replacement ($2.99 on eBay) I don’t think it’s worth it unless you just want a challenge. Just program like that or replace it... most times the pads get lifted up and it makes its FUCT (functional use completely terminated) or go ahead and follow this:
I have learned to make a point of soldering the USB sockets on Nanos down properly with real solder!