Now you lost me. First a definition. Retooling, to me, means keeping your core and adding to it. That's what they attempted to do this past summer.
If the main problem is found within the group of Tony, Manu, and RJ, how can you retool without breaking up the core? To take it to a further level of detail:
1. The RJ was an unequal or unbalanced trade. The conventional recap of that deal was that the Spurs increased the talent level of the team by accepting a significant increase in payroll. The Bucks saved money by losing talent. Trading RJ's contract now to improve the team would seem to be nearly impossible for the very same reasons. Trading his contract to reduce payroll may become possible, but that would be part of a rebuild rather than a retool.
2. Trading Tony has to net a PG in return. So where are the trade partners that would want Tony enough to send back a decent PG plus another player good enough to improve the team? I don't see it. Now trading Tony to a contender for a package of players with potential may be possible, but again that would be rebuilding rather than retooloing.
3. So we're left with treating Manu as an expiring contract and trying to find another unequal trade where the Spurs improve by assuming increased future payroll expenses. If you assume that Manu can't help the Spurs win any longer, then there would be some possibilities in this area, but no sure things ( Manu for SJax plus filler, for example). There is one big problem with this approach. If things are not going well with the retooling efforts from this past summer, I have serious doubts that ownership would approve even more spending to undergo a midseason retooling.
My best guess is that this is the group that we'll see all season, with the possibility of a minor tweak along the way. Based on how close this group comes to becoming a championship contender will determine whether we see further retooling next summer or the inevitable start of a rebuilding effort.