How to “crack” this position? I find this particular final position from a personal game intriguing. Even though there's a material advantage, there's no clear path to the victory. Does anyone have any good ideas on how to crack this nut?

[Event "Liga CS Jug"]
[Site "Niska Banja"]
[Date "2016.10.15"]
[Round "8"]
[White "Bojkovic"]
[Black "Djokic"]
[Result "1/2-1/2"]
[ECO "B41"]
[WhiteElo "2234"]
[BlackElo "2329"]
[Source "Analyze This (Free)"]
[FEN ""]
[startply "130"]

1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 a6 5. c4 Nf6 6. Nc3 Qc7 7. Be2 b6 8. O-O Bb7 9. Qd3 Nc6 10. Nxc6 Bxc6 11. a4 h5 12. h3 Bc5 13. Bg5 Qe5 14. Bxf6 gxf6 15. Bf3 a5 16. Rfd1 Kf8 17. b3 Rg8 18. Ne2 Rd8 19. Rac1 Ke7 20. Rc2 Bd6 21. Kf1 Bc5 22. Nc3 Rg5 23. Re2 Kf8 24. Ree1 h4 25. Nd5 Kg7 26. Ne3 Qf4 27. Ng4 Kf8 28. Qc3 Bb4 29. Qxf6 Qxf6 30. Nxf6 Ke7 31. Ng4 Bxe1 32. Kxe1 d6 33. Ne3 Bb7 34. Ke2 Re5 35. Rd4 Rg8 36. Ng4 Rc5 37. Ne3 Rd8 38. Rd2 Ba8 39. Rd4 Re5  1/2-1/2
I have been looking at this with a fairly strong computer for about 15 minutes (and the judgment of having been a Master for 30+ years and forcing in plausible lines), and I am convinced that this is a positional draw.

White is obviously worse per the computer eval, but he can keep the position exactly as it is by either moving his K from e2 to d3 and back (sometimes f1 if there is a threat to take on g2), or his Rd4 back and forth to d1 if black moves the Re5 away so e4 is not hanging. So, that leaves only to look at what can black do.

You have to look at black's pawn breaks. Clearly, b5 is out as cb actually leaves white better. d5 just loses. f5, which would be the standard try, is never any good because after ef and the bishop trade on f3, that will leave a monster N to go to d5, and that will also keep black tied to the weak pawn on b6. That only leaves the attempt to double rooks on the g-file, and sacrifice on g2, but it is already defended twice, and can even be over-protected with Kf1 if it looks like it might work for black.

Lastly, on top of b6 being weak if f5 gets played, h4 also becomes an immediate target along the fourth rank.

My opinion is that if black tries to win, especially with f5, he is probably going to be worse, and it will be he, who is fighting for the draw. Sorry, I just do not think that there is a way to crack that nut. Try too hard, and you might break an egg though. :)