Your specs are more vague than you think they are.
Assuming you want to replace any positive integer immediately after that specific I:max= with 987 and any positive integer immediately after that specific I:min= with 654, then it could be done with something like:
FIND = (?-is)(Size\s+{\s*.*\R\s*I:max=)\d+(\s*.*\R\s*I:min=)\d+
REPLACE = ${1}987${2}654
SEARCH MODE = Regular Expression
REPLACE IN FILES
hopefully, you can figure out what to change in order to replace with values other than 987 or 654
highly recommended: always back up your data before trying a regex that someone hands you; always try a new regex on a single file and make sure it behaves as you expect before trying on the full 30 files.
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