How to cure red bumps on the head of the penis?

No need to treat: "pearly penile papules" are a normal finding in many men, especially if uncircumcised. Often referred to as "tyson's glands" although not glands. An occasional dermatologist might try to eridicate them with laser, under local anesthesia. But, this is entirely unnecessary. Bumps are not a sign of any disease and do not require any treatment.