In this rule

Historical Rules · 14 June 2019

Rule 114.7c

Official source text from the 14 June 2019 Rules release

Permalink

If an effect allows a player to “change any targets” of a spell or ability, the process described in rule 114.7a is followed, except that any number of those targets may be changed (rather than all of them or none of them).

Find this number in the current Rules