Benny,
The drag is under the cap on the stern (back) of the reel body.
Remove the end screw and remove/tip out all the drag washers....make a note of the way they are stacked and which end of the stack goes in first.
The stack will comprise of alternate metal and fibre discs around the size of a shilling (5p)
mg:
Wash the whole stack in petrol to degrease, the carefully clean each one by laying flat on piece of kitchen paper, take care the fibre ones can be very brittle.
Check the metal washers for corrosion, if you find corroded areas polish them smooth with fine emery paper 800 - 1000 grade is ideal and clean again.
Next clean out the end cap thoroughly.
Reassemble with a touch of Locktight on the retaining screw and your good to go.
Any problems comeback.
.
No relationship whatsoever to Peters ex.