...
With the supply reel mounted on the left, and with tape spooling off the left side of the reel as it turns CCW,...
[tape travel in normal play is from left to right]:...
Thread tape DOWN and UNDER the LEFT tension roller,...
UP and OVER the LEFT idler roller,...
UNDER the tape guides and headstack,... (remember to open the RFI shield on the head assembly),..
BETWEEN the CAPSTAN and PINCH ROLLER,...
OVER the TACH ROLLER,...
UNDER the RIGHT tension roller,...
& spool tape UP and onto the takeup reel, while turning it in a CCW direction.
