Can you explain the rulings of madd al laazim, still a bit confused with that?

Can you explain the rulings of madd al laazim,still abit confused with that, and also is there an easy way of remembering how long one should elongate for each rule? The original madd rule is quite simple as its 2 harakaats long so are the followers of madd at tabi'i, but madd al fari'i gets difficult as some you have to elongate six counts and some are only 4 - 5 how can one remember this?

Wa alaikum assalaam wa rahmatullahi wa barakatuh,
If a medd letter is following by a hamzah, then for Hafs 'an 'Aasim by the way of Ash-Shaatibiyyah, we read the medd with four or five vowel counts.  This can be within a word, or between two words.

If the medd letter is followed by a original sukoon (meaning the sukoon is present whether we are stopping or continuing, included in this is the shaddah) in the same word we lengthen the medd six vowel counts, and this is the medd laazim.

If the medd letter is followed by one letter, and that last letter has a vowel, but we are stopping on the word, we change the vowel on the last letter to a sukoon and stop with 2, 4 or 6 vowel counts.