Stihl Kombi Tiller Model BC 30 seized

I have the Stihl Kombi with a Model BC 30 tiller. Everything is about 15-20 years old. The tiller seized or locked up today. Engine runs just fine but the tiller is locked up. Cannot budge the tines.
Any and all help or advice will be appreciated.
Thanks in advance for your time & effort.
Warren