If you decide to re-image (a wise decision), then do NOT re-image your existing microSD card. Instead use a spare microSD card.
Using a spare microSD card for re-imaging has the advantage that if anything goes wrong or stuck with re-imaging, you can restore your system and prevent your streak from breaking by slipping out new microSD card, and slipping in the old microSD card and powering up.
Please see following guide:
How to Install and Configure Piaware 5.0 SD card image - Quickstart Guide
EDIT:
If your existing install has other feeders also (such as FR24, Planefinder etc), then please see this guide:
Re-imaging Made Easy