You only have to loosen the two nuts/bolts (arrowed in the picture) ...
This enables you to move the alternator enough to replace the fan belt.
The lower one can be rusted solid in the bracket/alternator.
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<font color="blue"><i>1981 TR7 FHC Sprint (better known as 't Kreng)
1981 TR7 DHC (not very well known yet, but back on the road)
Also a 1980 TR7 DHC, 1980 TR7 DHC FI, 1981 TR7 FHC</font id="blue">
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http://tr7beans.blogspot.com/</i></font id="red"></center>