 That led to the restoration of the exterior over the next year, part of a $6 million campaign that began in 1987.Work on the stained glass windows proved particularly challenging because the original installers had forced them into spaces too small for them, making them hard to remove.It was necessary to hire more than the usual number of restorers, work overtime and locate the workshop in the dome rather than offsite in order to meet the church's fall 1997 deadlines.