Just specify that the separate property is given to the other party.
Then the situation is automatically reflected on the Marital Property Division screen.
Let us illustrate in a case that has only one asset.
It is a real estate property worth $500,000 (no mortgage, for simplicity), in which the wife has a $100,000 separate interest that she is giving to the husband.
1. Enter the separate property, as shown below:

2. Specify that the separate property is given to the other party.
Click “more info” (green 3-dots button) at the bottom of the section. In the screen that appears, specify that $100,000 — the wife’s full separate property interest — is being given to the husband.

2. On the Analysis tab, go to the Divide Property screen.
When you go to the Divide Property screen, you will see that the husband is treated as having received $100,000 of marital property and the wife is treated as having given up $100,000 of marital property, as shown below:

The situation is equalized by giving the wife extra — in this case $300,000 of the $400,000 of Marital Equity.

So just go ahead and use the Divide Property screen.
When you have equalized the distribution, the impact of the separate property given to the other spouse is automatically handled.