How to install TWRP if usb device not recognised?
Since you already have a version of TWRP flashed and working, you can use it to flash your new recovery image without the aid of a PC. 

Boot into TWRP, select Install and follow the screenshots for the rest.

(Click an image to enlarge it)





If you know where the recovery partition corresponds to under /dev, you can also use TWRP's command-line feature.