Fixing adverbs are provided in this article. The words listed here are commonly found along with the verb fixing in sentences. This reference page helps answer the question what are some adverbs that describe or modify the verb FIXING.
definitely
finally
firmly
merely
simply
Hope this word list had the fixing adverb you were looking for. In addition to adverbs used with fixing, other example verb adverb pairings can be found on this site.
You can help by adding more adverbs in the comments. Thanks.