The work was carried out by contractor Bam Nuttall over the weekend of September 25-26, with teams working round the clock during a 54-hour closure of the line, to allow the bridge sections to be craned in safely.
Six sections making up the main framework of the steel bridge and lift-towers were successfully positioned, with the largest section, the main bridge span, being 16m long and weighing more than 28 tonnes.
The bridge sections, including the main, upper and lower spans and the two lift shafts had been delivered to site under police escort from Coatbridge via the M8 and A1, before negotiating the narrow streets of Reston village to get to the site.
Barrie Forrest, chairman of the Rail Action Group East Scotland (RAGES) was delighted to see the footbridge taking place.
He told The Berwickshire: “We are all absolutely thrilled to see this milestone moment take place.
"We have been campaigning for this for more than 20 years, and it should really have been in place 10 years ago, but it’s wonderful to finally see it taking shape.
"I see they are doing groundwork now for drainage and the entrance to the station, and we hope to see the station open by the end of the year, but it might roll over due to weather.
"Transpennine has already told us they are going to do five trains each way, and will do another two come the May timetable, and we hope that LNER will do an extra late train at night and an early one in the morning.
"I'm lucky enough to remember getting on the train at Reston, and this will be a huge benefit to this area.”
Lisa McKenna, Network Rail project manager for the Reston station development said: “Installation of the footbridge marks a major milestone for the project’s delivery and we are grateful to the team at Reston for completing this challenging element of the project safely and efficiently.
“The bridge and lifts will help deliver easy local access to East Coast mainline services and will make this area more attractive for inward investment and housing growth, which will both support local communities and the economy.
“Work will now continue, both on the bridge and the wider station development, which will help open Reston to new opportunities and transform this community.”
In addition to the installation of the bridge, work was also carried out to upgrade the overhead lines through the new station to make the most of the access to the line.
The plans for Reston will see the construction of a two-platform station on the East Coast Mainline, with 70 car parking spaces and a new access road. The station itself will be fully accessible with the lifts and footbridge connecting both platforms.
Completion of the station will see trains call at the Borders village for the first time in more than half a century.
Jerry Dickson, operations manager at BAM Nuttall, added: “We’re delighted to be under way in creating another brand new station for Scotland’s Railway. BAM has a proud history in delivering new rail infrastructure in the Borders and we’re looking forward to helping even more of the region to access rail transport.”