LG Optimus G E975 has no SD card. How can I install Operating Systems on it?

[i sharp]

I am still using an LG Optimus G E975 (a bit old now) phone. It has no card slot and therefore I cannot use SD cards with it. What options do I have to install Android Lollipop, Touch Ubuntu, etc. on my phone (or even re-installing the same Android 4.1.2 again on the phone) without having an SD card? Can I dual boot LG Optimus G E975 so that I can have both Android and Ubuntu?