** Bird nests have clogged up the vent. I was told I may need to have the dryer vent relined or rerouted. **
By whom? I don't know what relining a dryer vent would be.
But if you were told by an appliance service technician that the venting needed to be altered, maybe you should consider having the installation changed. If you weren't tole by an appliance service technician, call some local appliance service depots to see if they do dryer vent cleaning and ask them to come to inspect it to provide their opinion.
If it does need to be replaced, a general contractor might be needed, preferably one familiar with proper dryer venting (see the following link). Some appliance service depots might do it as well but generally they only work on the appliance itself only.