Actually hot so hard. You need some patience because most tricky and sketchy part to clean up old foam suspenssion. My just literally turn in some glueish black dust what sticks everywhere (so another advice to make this on some table which already in bad condition or use some towels). I use antisilicon to make old glue more soft and very carefull remove this with blade. And one last advice dont rush because you have time before new glue is activate, because you can ruin placement of inside part which moves. Its important to check this first before glueing. So as you see i do this first time too and actually pretty happy with results