Unable to install OpenWrt using SSH or Web gui

I was told by Linksys support that my WRT1900ac V2 router cannot be be flashed with OpenWRT or any third party software. Only the V1's have that capability. So how is it that so many of you have it on a V2? Has any body had that issue and/or how do I install anything?

What did you try to flash?

There is a V2 image.

Thanks for the quick reply.

  It is the one for the first install. Version 2.  It starts to

upload and about halfway it stops and says to try again. Even when
I used the earlier Linksys version in the router and tried to
upload the latest firmware manually it did the same thing. I
connected the WAN port to the internet and used the automatic
update and that worked.