The Present Perfect Tense is in fact a past tense meaning I have done something.  It is formed by using the present tense of the verb HABER (to have done something)  + Past Participle.  

The Past Participle is formed by removing the AR from the infinitive and adding ADO e.g. He hablado – I have spoken.

The Past Participle is formed by removing the ER or IR from the infinitive and adding IDO e.g. He comido – I have eaten.