Both of my 1988 Fiero front speakers are original... therefore, they have been missing their foam for some time now.
I began by removing the speaker and prying off the grill that directly covers the cone.
Then cleaned off the old debris using a brass brush, though any brush other than a steel one should be fine.
A flat x-acto blade to remove the old adhesive from the metal frame.
Once all of that was done, I used a cloth to wipe the dust and remaining debris from the surfaces that would be taking tape.
Use something to pull the cone up and center it while applying the tape. Once you have a few supporting sections on, remove your props.
Work your way around the cone one section at a time, periodically push on the cone to make sure it is moving up and down with ease.
I have posted multiple pictures which will serve better than words. The end result wasn't a fantastic sound, but I was able to crank it all the way up without distortion, though a bit muffled.