How to check grease in manual steering box ??

[Green Machine]

I used to know how to do this but it's been years, so how do you do it ? I think some bolt(s) come out the top but which one(s) and is gun grease ok or is that like 75-90 rear end lube ?? This box is good yet so I'm delaying the power sterring for a while. Also how many are there still running the manual box ? or have most coverted to power ? I converted my 68 but it didn't know the manual box was worn out and binding till after I removed it. My 70 steers pretty good yet with manual, so i asume box is good yet. Thanks.