All of you that have already certificates can skip these instructions (1) and (2)
openssl pkcs12 -in export.p12 -clcerts -nokeys -out $HOME/.globus/usercert.pem openssl pkcs12 -in export.p12 -nocerts -out $HOME/.globus/userkey.pem
The user certificate can safely be world readable, but userkey.pem must only be readable by you!
chmod 0400 $HOME/.globus/userkey.pem