To drain the oil, you can remove the plug from the bottom of the crankcase with the mower up on some blocks over a pan.
Or just place the wheels up on blocks and tip the entire mower sideways towards the front of the engine (discharge chute side of your mower) and let the oil drain right out of the dipstick tube - you probably want to leave the dipstick cap on and then drain the remaining gas out of the tank first. Then do the oil.
When refilling the oil, it is a bit tricky reading the dipstick, both due to the clean oil which is hard to see on the stick, and also due to the fact that one side of the stick will almost always read higher than the other because it is up against the side of the tube. Always look at both sides of the dipstick and read the level from the lowest side. Wait a minute after adding oil for the level to stabilize and drain down the tube. When reading the stick, always wipe it clean first and then recheck the level - for some inexplicable reason, oil seems to creep up the stick when the mower just sits there (at least it does on most of my Briggs motors, esp. on the riding mowers).
Your carb (assuming that the pic in your profile is of your new mower) has a diaphragm-style pump in it and these are known to fail (especially at that age). You can get a repair kit for very reasonable, and detailed repair instructions are readily available online. In the short run, you may have some success by using some Seafoam in the gas, and also by adjusting the mixture screw, which is accessed through a hole in the fuel tank support bracket, to the left and up from the spark plug.
The self-propel mechanism is easy to work on - parts and instructions are also available online (do web search and you'll probably find plenty of pictures as well). If it works now, I wouldn't mess with it for the time being. There are several bearings which are replacement items, as well as the rubber friction ring and the belt. You can always mow without all of this working anyways.
I'd suggest downloading a service manual if you haven't done this yet.
Or just place the wheels up on blocks and tip the entire mower sideways towards the front of the engine (discharge chute side of your mower) and let the oil drain right out of the dipstick tube - you probably want to leave the dipstick cap on and then drain the remaining gas out of the tank first. Then do the oil.
When refilling the oil, it is a bit tricky reading the dipstick, both due to the clean oil which is hard to see on the stick, and also due to the fact that one side of the stick will almost always read higher than the other because it is up against the side of the tube. Always look at both sides of the dipstick and read the level from the lowest side. Wait a minute after adding oil for the level to stabilize and drain down the tube. When reading the stick, always wipe it clean first and then recheck the level - for some inexplicable reason, oil seems to creep up the stick when the mower just sits there (at least it does on most of my Briggs motors, esp. on the riding mowers).
Your carb (assuming that the pic in your profile is of your new mower) has a diaphragm-style pump in it and these are known to fail (especially at that age). You can get a repair kit for very reasonable, and detailed repair instructions are readily available online. In the short run, you may have some success by using some Seafoam in the gas, and also by adjusting the mixture screw, which is accessed through a hole in the fuel tank support bracket, to the left and up from the spark plug.
The self-propel mechanism is easy to work on - parts and instructions are also available online (do web search and you'll probably find plenty of pictures as well). If it works now, I wouldn't mess with it for the time being. There are several bearings which are replacement items, as well as the rubber friction ring and the belt. You can always mow without all of this working anyways.
I'd suggest downloading a service manual if you haven't done this yet.
