Timing off, need help adjusting

Hi there. So long story short. I got my 90 Integra around a year ago, and just before buying it the timing belt was done. The previous owber said said “Ever since they had the timing done it hasnt ran the same, but not TOO bad” so I figured last night id finally check the timing and go figure its off 1 tooth.

So my question is basically this, how would i go about adjusting the timing belt from here? I have the valve cover and upper timing cover off. Do i loosen the t belt tensioner then adjust from there, then retighten the tensioner once its in time?

Sorry for asking silly questions, but unfortunately i dont have the funds to replace the timing belt currently so adjusting is currently my only option and ive never done messed with Honda timing belts before.

I haven’t done a timing belt in a while so I can’t offer a suggestion here, but do you know if even the correct parts were used?

As far as Im aware, they should be the correct parts. It just appears with the crank and cams at TDC my Intake cams is off by 1 tooth and was hoping to fix that without having to replace the belt at the current moment.