Correct configuration for PSV testkit update via MTP

I have recently found that the configuration for MTP update is changed after updating to 3.60 fw.
The old method (place pup file in My documents\PS Vita\Package\Update\) no longer works for 3.60 fw. C3-120XX error will show up no matter how hard I tried. I have tried PSP2UPDAT.PUP .PKG and PSVUPDAT.PUP but non of those file names work.

Does anyone know what is the correct configuration so that I can up/down grade the fw without using a web server again? Thanks!

 

https://wololo.net/talk/viewtopic.php?t=46264
I cant speak for MTP as I never got it to work, but you can look at this

 

Thanks PixelButts, this method is better than MTP.