The silly oil-down-the-seatpost idea wouldn't work anyway because the cups on a world sport and other bikes had a little plastic accordion between them. My '85 World Sport also had seals around the crank spindle. You basically have to disassemble it to get in there.

To remove the parts and inspect, you would need a crank puller as well as bottom bracket tools.

A question like this should be solved at parktool.com, sheldonbrown.com, or the local library. They will show the procedure with pictures.