GUI for RSPNVPK
Based on MrSteyk's RSPNVPK. To use, simply select the folder containing the VPK you want to patch, and then select a patch folder. The patch folder must follow the format outlined here. Everything after the section detailing how to delete a file can be ignored, as it is automated.
This tool creates backups of VPKs that are patched by default, be aware that if your VPKs are particularly large they could hoard disk space.