Question about capital gains tax

I understand that gains on capital gains up to €1000 are tax-free and after that I have to pay 25% tax. Let's say I have already achieved exactly €1000 in profit this year (e.g. through interest, dividends, sales) and have already realized it. Now I still have two blocks of shares. With one I'm up €1000 since I bought it and with the second I'm down €1000 since I bought it. If I only sold the Plus package I would only make a profit of €750. Now the question: If I he