You say this machine is headless. Is it at a remote location? If not, is it feasible to connect it to a monitor an keyboard for a few minutes? If so then you could logout, switch DE, and then log back in. That would hopefully set the DE you prefer as user default.
If that's not possible, then some of the solutions discussed here might be applicable.
In the US, many public universities allow access to the public, including use of computer terminals that will allow access to paid databases. In many cases, you could bring in a usb stick and save copies of articles downloaded from such databases, or at worst you could pay a small fee to print some stuff out. AFAIK, that kind of access varies state by state though, so you need to call university libraries near you to find out.