Search 'target' and replace all the 'target'

:%s/target/replacemnet/g

But one by one?

/target

search document for next match.

*

execute a search for the word under the cursor at that moment.

*nn

cycle through all matches, taking us back to where we started.

cw

delete to the end of the word and drop us into Insert mode.

Example

Tip4 Tip6