Hello,
I encounter an issue on my pentax A 28-80 lens (on a P30T).
Here are some pics: I think that a spider was inside and make its net !
I remove the front bezel with the cap of a shaving foam spray.
Then the lens came, more or less easily. A suction pad can help (look in the bathroom !)
On the back side, I remove the screws with difficulties; one has to be drilled.
Then unscrew the lens, and the bezel. No real difficulties neither.
The only big issue was with the pin which indicate the automatic mode for the aperture.
This small §#$! pin jump out off the lens, as it is only locked by the big bezel !
Once this one is removed, it stand in place thanks to the hand of God, in my opinion.
I spent nearly 2 hours to put it back in place.
So if you have to disassemble the lens, take care to block this pin (with some tape or blue tag for example).
By the way, I clean up all the lens, and the result is very fine now.