To install a new version of TeX:
1. Easy case, only PLAIN changes.
	do tex
and then SSAVE when it tells you to
	do tex(2)
and then type Y when it tells you to.
2. Harder case, a bug in TeX has been fixed, but INITEX needn't be changed.
Change the version number in TEX.CH.
	r tangle↔tex.web↔tex.ch↔tex.psc↔tex.poo
	ex tex
The loader will prepare some file xxxLNK.DMP; before proceeding, 
	ren tex82.dmp←xxxLNK.DMP
so that the upper segment gets a more aesthetic name. Then
	unprot tex82.dmp[1,3]
	ren [1,3]←tex82.dmp/prot=255
and return to (1).
3. Still harder, INITEX also:
Change its version number, then
	r tangle↔tex.web↔initex.ch↔initex.psc↔tex.poo
	ex initex
and if it says "TANGLE me again" then
	acc tex,sys
and rename tex.poo from the new one. After initex runs, say
	unprot initex.dmp[1,3]
and so on, reducing the problem to case 2.