Thanks for sharing this. It is very important for a Muslim to know how to read funeral prayer. There are mainly two points where Muslims have difference of opinion regarding praying funeral prayer:
1. Whether we should read Surah Fatiha in funeral prayer or not.
If we refer to Authentic hadiths on this topic, then I think there should not be an difference of opinion as it is clear that Prophet Muhammad peace be upon him) did recite Surah Fatiha in the funeral prayer. I will quote few hadiths below:
Narrated 'Ubada bin As-Samit:
Allah's Messenger (ﷺ) said, "Whoever does not recite Al-Fatiha in his prayer, his prayer is invalid.
Reference : Sahih al-Bukhari 756
In-book reference : Book 10, Hadith 150
If that's not clear then let's read another hadith directly related to funeral prayer and it is authentic:
Narrated Talha bin `Abdullah bin `Auf:
I offered the funeral prayer behind Ibn `Abbas and he recited Al-Fatiha and said, "You should know that it (i.e. recitation of Al-Fatiha) is the tradition of the Prophet (ﷺ) Muhammad
Reference : Sahih al-Bukhari 1335
In-book reference : Book 23, Hadith 91
Tradition of Prophet Muhammad (peace be upon him) in above hadith means it is the way of Prophet Muhammad (peace be upon him).
My Hanafi Brothers and sisters should read two hadiths quoted above and correct their way of offering funeral prayer. Pray it like prophet Muhammad (peace be upon him) prayed and he told us to pray like we saw him praying [Bukhari 631]
2. Should we have only one Tasleem to the right or two Tasleem right and left as we do in regular prayers:
There is evidence in the authentic Sunnah of the Messenger of Allah (peace be upon him) that at times he (peace be upon him) finished the funeral prayer with only one Tasleem to the right, and at times he finished the funeral prayer doing Tasleems on both sides (right and left); thus regardless of whether one does only one Tasleem or two, either way it would be in accordance with the Sunnah of the Messenger of Allah (peace be upon him). It is best in this case to follow the Imam. If Imam makes on Tasleem (like Imam in Makkah does) then follow the Imam and make one Tasleem. However, if Imam makes two Tasleem then make two Tasleem.
Regarding rewards of Funeral prayer:
Ibn `Umar was told that Abu Huraira said, "Whoever accompanies the funeral procession will have a reward equal to one Qirat." Ibn `Umar said, "Abu Huraira talks of a too enormous reward." Aisha attested Abu Huraira's narration and said, "I heard Allah's Messenger (ﷺ) saying like that." Ibn `Umar said, "We have lost numerous Qirats."
Reference : Sahih al-Bukhari 1323, 1324
In-book reference : Book 23, Hadith 81
Narrated Abu Huraira:
that Allah's Messenger (ﷺ) (p.b.u.h) said, "Whoever attends the funeral procession till he offers the funeral prayer for it, will get a reward equal to one Qirat, and whoever accompanies it till burial, will get a reward equal to two Qirats." It was asked, "What are two Qirats?" He replied, "Like two huge mountains."
Reference : Sahih al-Bukhari 1325
In-book reference : Book 23, Hadith 82
And Allah knows the best!
May Allah make us among those who follow the way of Prophet Muhammad (peace be upon him)! Ameen!
May Allah make us among those who attend lot of funeral prayers! Ameen!