tried shop vac, tried shop vac with a funnel that had closer circumference... any glue that would stick using a nail head probably wouldn't pull off w/o damage to cone. tried shipping tape... not enough sticking force. dried chewing gum was my last idea. picked up a very nice pair of 301 tweets, with one cap dented. should I not worry, send it to Bose, scrap it. I don't know if I could cut the cap away cleanly from the cone. Copa..!!
I'm back. OK, one other option I've used successfully is hot glue. There of course is a catch, or two depending on situation. Because the cap is plastic you'll want to put the hot glue on the tip of something else, let cool down a little (very briefly), then attach, let set, then pull the cap out. The hot glue you might be able to pull off without re-heating, but I'd be more inclined to heat with a hair dryer and only a little at a time.
The other options have worked for me, though I do like a dental pick as opposed to a needle. One they come in really sharp tips AND the tip is usually curved. After that you can seal the hole with nail polish, model paint or silicon.
Cutting out is very simple if you use a FRESH exacto knife. I've made too many errors using a used knife. Never again. However, I'd search for a replacement cap first. No point cutting out the cap if you can't find a replacement.
Finally, and the timing is wicked funny, I just finished doing DCR's of my drivers and the tweeters are 3.0 (4-ohm).
Also, the woofers are 3.2 (4-ohm, wired in series), where the 301 drivers I received are 6.2 (8-ohm). I'll go ahead and use them, but will do readings with DATS first to determine which will go where (top or front). Likely the one with the better bass response will go in the front due to a larger "sub chamber" than the top. I'll post images with further explanations. I'll continue my hunt for correct replacements.
id you check them just using a MM?