how do i restart a service on sme 7b4, such as
service httpd restart, which is used on 6
No, it's long been deprecated, and if it works on 6 you are very lucky.
how do i restart a service in 7
The same way as every other version - cd to /etc/rc7.d, then do:
./SnnNAME restart
For any supervised service, you could also do:
cd /service/NAME
runsvctrl t .
For the apache web server, NAME is httpd-e-smith.