How to keep the blade guard off the Circular saw blade when in use?

I would return it.

I need to know the make and model of your saw in order to help you.

Hard to say without seeing it but....wrong sized blade, bent blade, clamp missing or installed wrong, bent guard, or bent blade shaft. I'd look in that order. Hope that helps.

Simple, unpug tool. Remove blade and back flange. Remove circlip and lift off guard. Unclip spring. Re-fit new guard. Refit spring and circlip. Refit blade.

Remove the battery, take the blade back off and you will see the holes for the torsion spring. what you will have to do is start putting lower guard on but pretenstion the spring so it will fit back into the proper holes, it might be a benefit to remove the small bumper so that you can move the guard more. when installing the blade you don't remove the lower guard just retract it and slide the blade in place. Usually there is a retaining ring to hold the guard in place but I looked at a breakdown and didn't see one. Let me know if you need more assistance before voting please. Thank you

remove the blade and check for the inner flange that should be behind blade. also there might be a ring underneath the inndr flange. or check to make sure the flange is installed correctly.

No you do not need to holde the lower blade guard up. It should be spring loaded and move upward as it engages to piece being cut. depending on what you are cutting, you may need to hold it up to start the cut, but then it can be let back down while cutting. It is a safety feature designed to keep as much of the blade covered as possible during use.

Am I correct that this is a hand-held saw? Want to make sure of the terminology.

If so, the bolt holding the blade has right hand threads -- meaning it loosens by turning counter-clockwise.

Is there a blade lock? Are you using it?

The spring hooks onto the blade guard and wraps around the hub of the blade guard. It is orta hard to see but it will hook onto the guard.