Enter what you hold, the mix you want and how much you are adding. Get the orders to place at your broker.
When and how to rebalanceYou pick a mix, say 60% world stocks, 20% bonds, 10% emerging markets and 10% gold. Then markets move. After a good year for stocks, that 60% can become 70%, and you are taking more risk than you signed up for. Rebalancing brings every holding back to its target weight.
Every time you add money: put it into whatever is underweight instead of splitting it evenly. Outside of that, check once or twice a year, or whenever a holding is more than a few percentage points off its target. Rebalancing more often than that mostly costs fees.
With selling off, only your contribution is used. Nothing is sold, so there is no tax to pay, and the money goes where the gaps are biggest. With selling on, overweight holdings are trimmed too, so every holding lands on its target.
Import your trades and the rebalancer fills in your real holdings and live prices.