The regulator is built into the alternator. The assembly also supports the brushes. The latest alternators have all this under a plastic cover on the outside of the frame so it can be changed without removing the alternator. If your's has what appears to be a cover on the back, remove it and see if you can change the regulator-brush assembly without taking the alternator off. (Had to replace the regulator on my car at 58K when I got it. I'll bet the previous owner was left stranded also as the battery was also weak from being poorly charged for a long time. The high current lug on the wire to the battery was also poorly crimped so I cleaned and soldered it.)

Things inside, bearings etc., rairly fail so a new regulator with new brushes often fixes the problem.

If they are inside, you will have to remove the alternator and partially disassemble it to get the back frame off and replace the regulator. (Use a heavy tooth pick to hold the brushes in place during assembly.)
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'96 965 with 16' wheels at 105K. Had '85 745 Turbo Diesel for 200K.