I use the Bootloader V5 from

Http://www.sprut.de/electronic/soft/usboot/usboot.htm (German Page)

Https://goo.gl/Z53QYX (Translated Page)

This starts after the reset when RE3 is at GND, or when the EEPROM cell with the address 0xFE has the value 0xFF.

Drivers / Tools for Windows are included in the USBoot package (Not Tested),

For Linux I use a customized version of fsUSB (http://www.internetking.org/fsusb/), or Piklab.

The device has its own USB ID:

Bus 004 Device 002: ID 04d8: ff0b Microchip Technology, Inc.