Kenmore Whispertone model 116, 29512991

Question

I have a vaccum purchased around 1998 - the vacuum has stopped working - I have checked the continuity of the house (so I know the on/off switch works) - looking for recommended troubleshooting steps - also, how do I get into the vacuum to check the motor? Pull the retractor lever (I think there are screws under there)? could the motor have worn brushes?

thanks!