Started to field strip/ clean an old Marlin 336 after firing a few rounds yesterday. It has been a while since I had this gun apart, & I took out the lever release screw & a started taking out the lever before partially cocking it... Note to self - read instructions if I haven't taken a gun down recently....
Now the lever will not come out, & I cannot get it fully back in to work the action. The hammer is back, trigger will not pull to release the hammer. In the past, seems like I tapped the bolt out with a cleaning rod to release everything, but the bolt feels like it is fully engaged/ locked in place.
Any suggestions for getting the lever either back in or the rest of the way out?

The lever normally disengages the locking lug. If the bolt is completely closed it is likely locked in place, not that serious.

Tap on the top of the receiver and see if the locking lug drops and disengages from the bolt. You can reach in and pull it down too.

Once it is out of the way you might be able to simply tap the butt on the floor to get the bolt moving or you can use a cleaning rod or dowel down the barrel to push it back.

If the locking lug is out of the way, the bolt will move fairly easily.

Thanks - that did the trick - I jiggled the gun around a bit until the bolt came free of the locking lug, pushed the bolt out & the lever dropped free.