Where's the problem? Try the following commands:
[pre]
wget http://boinc.berkeley.edu/dl/boinc_4.43_i686-pc-linux-gnu.sh
sh boinc_4.43_i686-pc-linux-gnu.sh
cd BOINC
./boinc -attach_project http://einstein.phys.uwm.edu _account_key_
[/pre]
If you don't have wget there, try lynx or curl.
BM

Linux server with NO windowing package
)
Have a look at this BOINC doc.