If you want to inoculate the jars using a spore syringe, and you're using a polyfill lid filter, punch a small second hole into the lid and inoculate through it. During the pressure cooking and after the inoculation cover the hole with a piece of masking tape.
If you're using filter discs you can inoculate through the disc, in this case also put a piece of tape on the inoculation spot after the inoculation.
If you are inoculate with agar wedge or doing grain transfer, you take off the lid for the short time of inoculation.