The primary change God gave to Joshua was a
transfer of leadership.
After the death of Moses, God appointed Joshua as the new leader of the Israelites. This was a significant transition and a huge responsibility. God assured Joshua of His presence and support, and gave him instructions for leading the people into the Promised Land and conquering it.
In essence, God changed Joshua from Moses' second-in-command to the leader of the entire nation, bestowing upon him the authority and responsibility to fulfill God's promises to Israel.