Weve got an old cutler hammer panel with panel clips on the breakers, instead of the back plate hving tabs that hold the breaker in. weve got the new replacement breakers but it seems to also have a retaining bar with non-removable screws that might also hold in the breakers. any ideas sorry no pics yet. chris

There are bits avail to remove those screws, you will need to remove the center bar in order to remove/replace breakers if it is easy to do so removing the interior will make the job easier.When all done toss the bar.

Thanks thats what we thought, but it seems strange to lock in all 4, 2 pole breakers in the panel, original has 4pole 100amp, a 60 and a 40 2 pole. were adding a 40 amp for solar back feed and replacing the 4pole 100 with a 2 pole. chris

Those panels are a early design,"vintage" Zinsco panels had a means of locking the breakers in place also.

Those screws usually come out pretty easy with pliars. Most times they are not even tight. Of course, I am referring to the ones here in Arizona, where we don't get much rust.

The tool used to remove the screws holding the center vertical bar in place looks like a nut driver (I have one). The screws have a very small flat on the side of the rounded head that this tool grabs onto.
I'm sure you can find something (maybe vise-grips) to back the screws out.

There is a tool for removing "one way screws" .

I'll see if I can get a picture of the tool.
At first glance the socket part looks like a round hole but it does have two very small flats 180 degrees from each other.

yeah Ive seen the ads for the tool, but never held one, thanks the job is handed off to another, and thanks for all who helped and let me know that it is normal to remove the bar. chris