I found a way to do this but it is a pain in the ass. First you'll need the right tools. Basically what you need is two long thin sticks. I had gotten a little metal dental pick "deluxe cleaning tool" with my VB and this worked good. I also used a bamboo skewer, these are used for making kabobs and such and you can get them in the aisle that has cookware in the grocery store. Whatever you use, it needs to be as long as the glass part of the whip and thin enough to go all the way through . And, of course, you'll need a new screen.

First, you need to take the plastic tubing off of the glass part. Run it under hot water for a minute or two, this will help soften the plastic. Next, you need to break the vacuum between the plastic and the glass or you'll never get them apart. Just insert something thin in between the two. I used the end of the cleaning tool but a long thumb tack or small nail would work to. Don't try to pry the tube off with whatever you've inserted, you could tear the tubing. Just gently twist and pull and it should come off.

Once the tube is off you can start to put the screen in. The trick is to go at it from both ends. Push the screen in from the top with one of the tools and then use the other tool to push it back into place from below. Try to keep pressure on both tools at the same time to nudge it into place. It will take a few tries but you should get it eventually. It won't be as good as it was originally but it will work again.