These are the stripdowns for the Diana and Milbro rifles with the above numbers and the safety catch fitted. These are more or less G25 and G27 guns but maybe with different sights. Some have a plastic rearsight and some a metal one. Some have a barrel pivot bolt and lockscrew and some just the bolt. Some have a cocking arm pivot screw and some a rivet, so use common sense and read through this to save me doing 4 guides.

Remove the sights if you want to. Undo front 2 stock screws and rear one in front of the trigger guard. You can remove the rear trigger guard one if you want to take the guard off. Lift the action out of the stock. Undo the barrel pivot lock screw if it has one and then the barrel pivot bolt. Lift barrel and cocking arm away from the cylinder. If you want to remove the barrel plunger and spring, do it now. Press the plunger with a bit of wood and undo the small screw on the LHS of the breech block. Release the wood slowly and the plunger and spring should come out. Clean and lube and replace.
Undo the screw holding the plastic safety on and remove the plastic catch. Knock the metal endcap off the end of the cylinder (often tight and may need tapping). I'd then undo the trigger adjusting screw and remove the sear spring and the trigger spring. The adjuster screw has a circilp on it but does not need to be removed for this strip. Tap the trigger pin/cylinder pin out (checking that the safety pin is holding the sleeve in the cylinder) and remove the trigger. The trigger may need some wangling as the rivet may catch on the sleeve. Now get a piece of wood and press on the sleeve, while pushing the safety pin into the sleeve. Slowly release pressure and the sleeve should come out. Take note of how the safety goes into the sleeve. The guide, mainspring and piston should now come out of the cylinder. There are a couple of types of piston washer/buffer/nut set ups. Clean and lube and be ready to put the gun back together.