If they actually have a proper portfolio pricing model (to compute the available margin), and they're just missing one use case, then that should be relatively simple to fix. A few days, or a few hours if they really put their heart into it.
If they're completely lacking an option pricing model... they're just not going to add one overnight. They'll have to add a standard model (most likely Black Scholes), come up with an estimation of volatility to feed into it (you can extract it from the market; implied volatility), and also solve the problem of linking derivatives to their underlying. In any case this is not a simple arithmetic accounting issue.
