I assume your talking about Hi8?
The easiest option is to find a professional and pay them to do it. If the content of the tapes is important then there are lots of things to know to get the best quality footage and audio, and it starts with high quality player and digital capture devices.
If you really want to do it yourself then you need to find out what connections are on the camera and then find away to get those out puts into your computer.
Most Hi8 cameras have a firewire port, but it is a dead standard and hasn't been included on computers for nearly 10 years. You can get PCI cards, or Firewire to USB adapters, but reliability can be an issue.
The other common connection is a composite video/audio over RCA. But then you do need a proper capture card in the computer with RCA inputs.
Once you have the camera connected to the computer you then need some kind of video capture software. I've used Premier Pro in the past, but all the big mainstream NLE's have some kind of capture ability.
You can also get digital capture devices with composite inputs that will record a video signal to the an SD card. But the quality of the recorded footage is generally poor, heavily compressed and with low quality audio.