Create a blank grid with a spread sheet program. Fill in the given numbers then save as a new file.Make the given and solved numbers bold.
For the other numbers, use a subset of simple triplets (for example ‘159’) which excludes all other instances of the triplet’s components in a row / column.
When you get to a point where you have to guess, save the file with another name. If you come to a dead end, simple reload a previous version.