Hello Joe,
Thank you for your inquiry. You will require a new sleeve, however the spring re-installation is relatively simple. The purpose of the spring is to apply back-pressure on the lamp so that it doesn't drop to the bottom of the sleeve.
To reinstall the spring, simply drop the spring in a vertical position to the bottom of the sleeve. When you insert your lamp after the sleeve is re-installed, the lamp will sit on the spring to provide the back pressure it requires to function. As long as the spring is sitting vertically in the bottom of the sleeve, you're good to go.
If you require any assistance during the installation please do not hesitate to contact us.
Amber - Customer Services