It is not intended to be difficult. If you can truly say “I love you God, I want nothing of the sins or defects of this world”, then you have it. If it is partial then there are degrees of it, read below (at the end) and the Church doubles it.
Did you know you receive the indulgence (for yourself or the faithfully departed you designate) at the completion of the conditions only when in a state of grace, where sacramental confession is within about 20 days before or after that completion (good for many times).
1451 Among the penitent’s acts contrition occupies first place. Contrition is "sorrow of the soul and detestation for the sin committed, together with the resolution not to sin again."50
1452 When it arises from a love by which God is loved above all else, contrition is called “perfect” (contrition of charity). Such contrition remits venial sins; it also obtains forgiveness of mortal sins if it includes the firm resolution to have recourse to sacramental confession as soon as possible.51
1453 The contrition called “imperfect” (or “attrition”) is also a gift of God, a prompting of the Holy Spirit. It is born of the consideration of sin’s ugliness or the fear of eternal damnation and the other penalties threatening the sinner (contrition of fear). Such a stirring of conscience can initiate an interior process which, under the prompting of grace, will be brought to completion by sacramental absolution. By itself however, imperfect contrition cannot obtain the forgiveness of grave sins, but it disposes one to obtain forgiveness in the sacrament of Penance.52
[LEFT]Since by their acts the faithful can obtain, in addition to the merit which is the principal fruit of the act, a further remission of temporal punishment in proportion to the degree to which the charity of the one performing the act is greater, and in proportion to the degree to which the act itself is performed in a more perfect way, it has been considered fitting that this remission of temporal punishment which the Christian faithful acquire through an action should serve as the measurement for the remission of punishment which the ecclesiastical authority bountifully adds by way of partial indulgence.[/LEFT]