This is me installing the type 1 usb-c mod on an original New Nintendo 3DS. That's the model with the swappable back and front plates.  This one has a stripped screw.

Type 1 mods replace the original port, type 2 mods add a port, and pro mods retain the charging contacts. This has 5.1k ohm resistors on CC1 and CC2 restricting charging to 5v allowing use across chargers of varying strength. I do these mods as a mail-in service on ebay and etsy as BXDIY and diylightful respectively, I sell parts kits on all my shops so you can handle it yourself.
My links:
https://www.ebay.com/str/BX-DIY/
https://www.tindie.com/stores/bxdiy/
https://www.etsy.com/shop/DIYlightful/