The thing about seasonal regimens is that they only work in advance.
By the time spring is visibly here — the first warm week, the first green — Kapha has already liquefied and started to move. Beginning a lightening diet at that point is treatment. Beginning it now is prevention, and prevention is roughly a tenth of the work.
So this fortnight is a taper, not a switch. You are still in Shishira; it is still cold; your fire is still strong. But every few days, one thing comes down.
A reasonable order: reduce dairy first, especially in the evening. Then reduce quantity at dinner — the last meal moves earlier and gets smaller before anything else changes. Then reduce the heaviest grains and the richest oils, keeping the warmth but losing some of the density. Sweet comes down last, because it is the one you will miss and because a sudden drop tends not to hold.
What goes up as those come down: pungency, bitterness, movement. A little more ginger. A little more of the bitter greens. Ten more minutes of walking. The classical Kapha measures start gently here and are already in place by the time the season actually turns.
One more thing worth doing this fortnight, because it is easy and it works: put honey in warm — never hot — water in the morning. The texts single out honey as specifically Kapha-reducing, and specifically ruined by heat.