How do I apply for the reduced tax rate (section 34 (3) EStG)?

If you are over the age of 55 or permanently incapacitated, you can benefit from a further tax reduction:

The capital gain can, upon request, be taxed at a reduced rate on the amount exceeding the tax allowance for capital gains. This is provided it is the first time since 2001. The reduced rate is 56% of the average tax rate, but at least the basic tax rate of 14% (§ 34 para. 3 EStG).