Here we have two instances where there is some variation with respect to the word that. In the printer’s manuscript, scribe 2 initially dropped the relative pronoun that: he started to write “and the way I know that ye believe them is … ”, getting as far as the I; then he overwrote the I with a capital T (capitalized in order to cover the I ) and continued inline with hat (the rest of the word that). Thus scribe 2’s correction was immediate. The critical text will, of course, maintain the that after way.
The second textual change involves the loss in the 1841 British edition of the subordinate conjunction that after know. The that was restored in the subsequent 1849 LDS edition. The critical text will maintain the earliest reading here as well. For some discussion regarding the optionality of that after the verb know, see under Enos 1:17; also see the list of examples under that in volume 3.
Summary: Maintain in Alma 7:17 the two instances of that in “and the way that I know that ye believe them is … ” (the earliest reading of the text).