Installing an application? Maybe, totally depends on the current OS.
Installing a new OS (Android or other).
That’s going to be very hard. There are no standards for this type of hardware (it’s not like a PC where you can install a Linux Distro, a BSD or whatever and expect it to basically work because all PCs are more or less the same).
You’ll need to know the exact system on chip it uses and all the main peripheral devices (basically you need the electronic schematic diagram) and then hope it’s something either already supported by the Linux kernel or that is documented.
If you are not very good with both electronics and low level software you are unlikely to succeed (unless someone else has already done the hard work).
You could learn a lot by doing this though just don’t expect to get anywhere fast. In fact if you want to go that route I’d advise you to first learn how to build and understand Android on an already docuumented dev board.