Can't install recovery on gpad 8.3

Hi. I have the model v500 lg gpad 8.3. I had kit kat and I wanted to flash a lollipop rom by recovery. But I couldn't manage to install it, so someone in another thread here advised me to perform a downgrade to jelly bean and then install twrp so I can flash the lollypop rom. Well, there in no way I can install twrp on my G pad. I tried with rashr and twrp manager but I get error messages. I also tried with adb, but all I get is "adb is not recognized as an internal or external command".
The tablet is rooted, usb debbuging is on. Drivers are installed.
It's driving me nuts!!! I don't know what else to do. I know I'm doing something wrong, I just do not know what!!!
Could someone please help me??? thankss!!!

Gionee Gpad G4

Why there is no custom ROM for this device(Gionee Gpad G4). I found possibly all gionee models but why you leave this. Please think for this device.. please..:rolleyes:

LG GPAD 8.3 GPE (V510) Did anybody receive an OTA recently?

Hey guys,

I just received an OTA for a new update. Forgive me, but I left my GPad at home, so I don't know what the update file is.

Just wanted to know if anybody else got it? I don't want to lose root or it to mess up my tablet.

Thanks!