I mistakenly set the precision and scale for a "double" attribute field such that only one digit is allowed to the left of the decimal. After collecting ample data on a Trimble GPS, which didn't seem to enforce this limitation (the majority of entries in this field have 2-3 digits to the left of the decimal point...), I am trying to go back in ArcMap to make some edits (erroneous entries with up to four digits to the left of the decimal, which should only have two) but am not able to make such reductions in the number of digits. Ironic, since, in some cases I am attempting to reduce a four-character entry to a two-character entry, and am not allowed to do so and am told that I can only have a single-character entry. So I cancel and the entry remains at four characters...
My understanding is that once the rules are set for a particular field, they're immutable. Have you tried creating a new field with the rules you'd like, then using "Calculate Field" to set all the values as identical to the previous field's values? If you did that, then you could delete the previous field, and continue working with your field that's set up as you'd like.
The only thing that's annoying about this solution is if you want the new field to have the same name as the old field. Since you can't have two fields with the same name, you have to create an interim field with a different name, calculate field, delete the old field, create a third field with the original name, calculate field, delete the interim field.