air in rads

Hi. First time here AND a novice so will try to be succinct. Most rads in house working fine on both floors (ground and first). Except three on the first floor only heating partially at the bottom. The rads in question have two valves one at each end, a spindle like projection if you take the cap off. Do I unscrew the nut at the base of this spindle like valve to bleed the rads? Do I turn the valve at the other end of the rad off whilst I do this? Or have I got it (completely) wrong?

The bleed valve is always at the top of a radiator on the side or at the back and use a radiator key,leave both radiator valves open and pump off.

Thanks for that. I've just had a look and there's definitely nowhere for a rad key to fit. Having looked at all the rads it appears that only two have bleed valves and they are both on the ground floor. The ones upstairs don't have anything top or bottom, front or back. Mystified but appreciate your input. Gene

SORTED! Thanks Masona. The valves are tiny and recessed which is why I didn't find them first time round. Job done cheers.