Axe

wimerblanchard​  Start a new save and send a sim to China.  (You can pick a premade sim with enough money for traveling.)  Go to Edit Town, click the lot, and save it to the bin.  You can then quit without saving your progress in the new save.

You might need to use a cheat to be able to save the tomb lot; you'll definitely need a cheat to be able to bulldoze the lot in your existing save and replace it.  Bring up the cheats console (ctrl-shift-C) and add these cheats in order:

testingcheatsenabled true
enablelotlocking true

Then click the lock in the lower-right corner of the lot description you see when you click the lot in Edit Town.  Undo them in reverse order (false instead of true), or just leave them on if you like.

If you want to test without having to go through the entire tomb again, you can send your sim there, make sure testingcheats is active, shift-click the ground of the lot, select Build, and put in a door or two so your sim can go straight to the axe.  If it works, you can back out and do the entire tomb all over again, or just collect the loot and be on your way.

the axe

how do you  replace the tomb.  I tried buying it and it only shows up in buy or build mode.  not live

wimerblanchard​  What do you mean it won't show it to you: that the axe isn't on the wall, or something else?  If it's not showing on the wall, try quitting and restarting the game, and make sure walls are up so you can see where the axe is supposed to be.  When you save before quitting, use "save as" and rename the save so your previous version doesn't get overwritten—you might need it.

If that doesn't help, are you willing to quit without saving and redo the tomb?  You might need to replace the lot to make the tomb work properly.  If you've saved too recently, it might still be possible to fix the issue by replacing the tomb, but let me know.