10-years old dark brown pull up leather couch - sun exposure, skin oils, drying and cracking - any suggestion?

[Questions!]

Hi there,
I have a 10-years old dark brown pull up leather couch. Due to a combination of sun exposure, skin oils, and lack of cleaning or maintenance, the leather is deteriorating, with drying & cracking on the cushions, and skin oil stains and/or deterioration on the armrests and seatbacks. Any suggestions? The Kit-Aw3 looks comprehensive, but it seems very technical. Maybe I don't need the whole kit, but just specific products. Appreciate your advice with restoring this couch.
Thanks,

#1



#2



#3



#4



#5



#6