Hi Rick,
It depends on what exactly are you looking for. If you want to simply remove certain characters/words from the search phrase, before the search query is executed, then these knowledge base tutorials may help you:
– Replace or remove characters from search phrase
– Replace search keywords (whole words)
There are also two options on the back-end, that allow excluding words (or even single characters), but I don’t recommend those for other than alphanumeric values. In case you need to remove special characters, use the custom code in the examples above.